Process of preparing hexahydronaphthalene



Patented July 11,1950

PATENT OFFICE .PRQGESfi E HEXAHYDRO- N PHTHALENE AlanBelL Kingsport, Tenn., assignor to Eastman Kodak Company, Rochester, N. Y., a corporationo'f New Jersey No prawing. Application April 14, 1949, ,Serial No. 87,573

2 Claims.

OOC.CHa

and disclose a method of making it, as follows:

Example I. 1,4 dihydroxy-decahydronaph- Malena-350 g. of 1,4-dihydroxy-5,8-dihydronaphthalene was dissolved in about 1000 cc. of methanol and reduced at 125-150 C. for 6-10 hrs. under 1000-150 lbs. pressure with hydrogen, using Raney nickel as a catalyst. The resulting solution was filtered immediately after being taken out of the bomb, and the methanol was removed under reduced pressure in an atmosphere of nitrogen. The syrup thus obtained consisted of a mixture of the cisand trans-isomeric forms of 1,4-dihydroxy decahydronaphthalene.

Example II. 1,4-diacct0xy-decahydronaphthaZene.The crude syrup containing the mixture of isomers, prepared in Example I, was refluxed for two hours with 1500 cc. of acetic anhydride. The cooled solution was poured into 3 liters of water. The resulting insoluble oil Was separated (ether is used if necessary and the ether solution dried over CaClz) and distilled. The product is a pale yellow, very viscous oil, B. P. about 150 C./1-2 mm. Yield 400-450 grams.

I have discovered that a hexahydronaphthalene having the physical constants stated in the first paragraph of this specification can be prepared from 1,4-diacetoxy-decahydronaphthalene by passing the latter through a tube heated to a temperature of 400-500 C.

Example III.Herahydronaphthalene.-350 g. of the mixed cisand trans- 1,4-diacetoxydecahydronaphthalene prepared in Example II was passed through a tubular furnace packed with Pyrex glass tubing and heated to 450-500 C. The resulting product was poured into water, and the insoluble layer was separated, dissolved in ether, washed, dried over CaClz and distilled. el .Q color ss 0. 1.13.- -65/ 11 11 155 Analysis 0 H Per cent Per cent Caled. for CmHu 89. 5 10.5 Found 89. 6 10. 8

B. P. 199.5 C., (14 0.9414, N13 1.5210.

I have investigated the chemistry of this hexahydronaphthalene by subjecting it to the Diels- Alder reaction, with benzoquinone and with maleic anhydride, as follows:

Eztample IV.He:rah;L dr0naphthaZene-benzoquinone adduct.-7.0 g. of the hexahydronaphthalene prepared in Example III and 5.4 g. of benzoquinone in 50 cc. of benzene were refluxed for four hours. This solution was filtered to remove 1.5 g. of a quinhydron and then evaporated. The resulting yellow crystals were triturated with naphtha and filtered. Yield 6 g. After recrystallization from methanol, the product had a melting point of 96 C.

Analysis 0 H Percent Percent Calcdi for the addition product 79. 3 7. 4

Foun 79. 0 7. 8

Example V. H exahydronaphthalene-maleic anhydride adduct.-7.0 g. of, the hexahydronaphthalene prepared in Example III and 5.0 g. of maleic anhydride were refluxed for four hours in 50 cc. of benzene. The benzene was evaporated and the residue triturated with naphtha. Yield 5.6 g. After three crystallizations from methanol, the product formed White crystals, M. P. 91 C.

Analysis 0 H Percent Percent Calcd. for the addition product 72. 4 6. Found 72. 3 7. 2

a l i 9,IO-etheno-M-dodecahydro-1,4-anthraquinone and 1,4 etheno-decahydronaphthalene-2,3-dicarboxy1ic anhydride 4 However, due to the confused state of the literature on the hexahydronaphthalenes, in the attached claims I shall identify the hexahydronaphthalene prepared by my process by its physical constants rather than by the positions of the added hydrogen atoms. What I claim as my invention and desire to be secured by Letters Patent of the United States 1. A process of preparing a hexahydronaphthalene having the physical constants: B. P. 199.5 C., d4 0.9414, ND 1.5201, which comprises passing 1,4 diacetoxy decahydronaphthalene through a tube heated to 400-500 C.

2..A process of preparing a hexahydronaphthalene having the physical constants: B. P. 199.5 C., d4 0.9414, No 1.5201, which comprises passing 1,4 diacetoxy decahydronaphthalene through a packed tube heated to 450-500 C.

ALAN BELL.

No references cited.

Certificate of Correction Patent No. 2,514,365 July 11, 1950 ALAN BELL It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 23, for 150 lbs. read 1500 lbs.; column 2, line 10, for 1.5210 read 1.5201;

may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 10th day of October, A. D. 1950.

THOMAS F. MURPHY,

Assistant Ummm'ssz'omar of Patents. 

1. A PROCESS OF PREPARING A HEXAHYDRONAPHTHALENE HAVING THE PHYSICAL CONSTANTS: B. P. 199.5*C., D4**20 0.9414, ND20 1.5201, WHICH COMPRISES PASSING 1,4 - DIACETOXY - DECAHYDRONAPHTHALENE THROUGH A TUBE HEATED TO 400-500*C. 